Rotary compressor or supercharger



4 Sheets-Sheet 1 Ni/ENTOR Er'llng Borshng.

Jan. 14, 1947.

E, BORSTING ROTARY COMPRESSOR OR SUPERCHARGER Filed April` 19. 1943 imam Jan. 14, 1947.

E. BORSTING ROTARY COMPRESSOR OR SUPERGHARGER Filed April 19, 1943 4 Sheets-Sheet 4 aclllllll.

Fig. 11

l /N VENTO/e Erhn Bors l BY CbJK'W 1g ng A TTORNE V5 l supercharger.

Patented Jan. 14, 1947 Erling Borsting, Mount Vernon, Ohio Application April 19, 1943, Serial No. 483,589

2 Claims. l

My invention relates to a rotary compressor or It has to do particularly with a reversible compressor or supercharger adapted to use as a scavenging blower for two-cycleinternal combustion engines, although its use is not necessarily so limited since it is equally well adapted for use as a supercharger for two-cycle or fourcycle engines, as well as a rotary pump for-liquids, such, for example, as oil.

The reciprocating type of scavenging blowers of the prior art which are used on two-cycle engines are directly reversible and therefore are suitable for reversible engines. This type of blower is necessarily very large and therefore not suitable for use with high speed engines. Heretofore, high speed engines have used some form of rotary compressors or blowers, usually the Roots type.` Rotary compressors or blowers are not reversible for the reason that if their direction of rotation is reversed the air flow is also reversed and therefore the blower could not be used with a reversible engine because the air must always be pumped or forced into the engine. Such blowers have thus necessarily been equipped with reversing valves of large size because of the largevolume of air which the blower had to handle. Reversing gears have also been employed but such gears add materially to the cost and substantially increase the size of the unit. Therefore, there is a distinct need for a directly reversible rotary compressor for use with reversible high speed engines, particularly marine engines.

My present invention makes it possible to reverse the slidingvane type of rotary compressor without materially increasing the size ofthe unit. The sliding vane type of rotary compressor can be made to compress the air before discharge which makes for high efiiciencyand quietness of operation.

One of the objects of my invention is to provide an improved rotary compressor, blower, or supercharger which is capable of being driven in either direction.

Another Objectis to provide an improved compressor, blower, or supercharger which, regardless'of the direction of rotation of the rotor or impeller thereof, will always draw in the iluid, such as air, through the intake opening, compress it,l and discharge it through the exhaust opening.

Another nobject is to provide an improved compressor of the foregoing character which automatically reverses its direction of rotation upon .(cl. 23o-152) 2 the reversal of rotation of the power plant or other instrumentality to which it is connected.

Generally speaking, the compressor, blower or .supercharger embodying my invention, as shown,

consists of a housing or casing; one side thereof having an intake opening and the other side anl exhaust or discharge opening. A drive shaft is mounted in suitable` bearings carried by hangers located within the housing and carries a rotor provided with a plurality of preferably linedvpockets in which slidable vanes or blades are located. The shaft and the rotor are arranged eccentrically within the housing. Interposed between the housing and the rotor is a cylindrical member or cylinder having a plurality of ports'formed therein and with which the vanes coopera-te to compress the air or other fluid entering through the intake opening. The ports in the cylinder are adapted to align or register with the intake and exhaust openings and since the cylinder is free to be rotated automatically through approximately 180 degrees at predetermined times, it will be seen that diierent ports therein align or register with the intake and exhaust openings de- 25 pendent upon the position of the cylinder with relation to the housing. Regardless of the position of thecylinder, however, the air is always admitted through theV intake openingand discharged through the exhaust opening of the housing.

The exhaust side of the housing is provided with a plurality of longitudinally spaced ribs which align with and at certain times cover some,

of the ports in the cylinder so as to always discharge the compressed air through the exhaust opening in the housing regardless of the direction of rotation of the rotor.

To reduce friction and consequent wear and overheating, the vanes of the rotor are main` tained out of direct contact with the wall of the cylinder. For this purpose I preferably provide the opposite ends of the vanes with notched-out portions which support rockable bearing blocks which may be made from some suitable self-1ubricating metal. These blocks engage floating rings at opposite ends of the rotor and the rings are free to rotate on suitable bearings. Due to the contact of bearing blocks carried by the end portions of the blades with the rings, these rings are forced to rotate although there will be some slippage and the rings and the rotor will not operate at the same speeds. The net results of 'this will be that only a small fraction of slippage will occur as compared to the amount of slippage which would result from theuse of a stationary ring or rings. The free edges of the varies are maintained spaced slightly away from the cylinder' wall.

If it should appear to be desirable to prevent leakage of the indrawn air or other fluid, I may provide each of the rotor vanes with a strip-like member or piece of some suitable material such, for example, as fiber, hard rubber, Bakelite or other suitable material. These members engage the inner wall of the cylinder and upon operation of the rotor, wear themselves in so as to follow the contour of said inner wall.

The invention, therefore. comprises a relatively small, compact and simply constructed reversible rotary compressor, blower or superdharger in which friction is reduced to a minimum by virtue of my improved manner of lubrication of theparts. Due to thereduction of friction and the proper lubrication of the parts, there 'is virtually no wear',l thus the life of the unit is greatly prolonged. These features having to `do Vwith the support of the vanes and the lubrication, would apply equally well if the compressor were cap'able of operation in one direction only The above and other objects and advantages will'appear from the following description and appended claims when considered in connection with the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In said drawings:

Figure l is a vertical longitudinal sectional view through my improved rotary compressor or supercharger, taken substantially along the line l-l of Figure 2, looking in the direction of the arrows.

Figure 2 is a transverse vertical sectional view taken substantially along the line 2-2 of Figure 1, looking in the direction of the arrows.

Figure 3 is a view similar to Figure 2 and showing the' rotor in a position opposite to that in which it is shown in Figure 2.

Figure 4 is a horizontal longitudinal sectional view, partly in elevation and partly broken away,

of the rotary compressor or supercharger of the preceding views.

Figure 5 is a vertical sectional view of the drive gearing taken substantially along the line 5-5 of Figure 4, looking in the direction of the arrows.

lFigure 6 is a vertical section taken substantially along the line 6-6 of Figure 4, looking in the direction of the arrows.

Fig. 'I is a vertical sectional view taken substantially along the line 1--1 of Figure 4, looking in the direction of the arrows.

Figure 8 is `an enlarged transverse sectional view of the rotor and cylinder assembly.

Figure 9 is an enlarged elevational view, partly in section, of the rotor, illustrating the arrangement of the lubricating means. 4

Figure 10 is a fragmentary sectional view, on

I an enlarged scale, illustrating a modified form of rotor vane or blade.

Figure 11 is a fragmentary perspective view, partlybroken away,`looking at the exhaust side gf the rotary compressor embodying the invenion.

Figure l2 is a perspective view of one of the vane's or blades of the rotor, partly broken away, showing the rockable bearing blocks attached to its opposite ends.

Figure 13 is a perspective view of a portion of the cylindrical member of the compressor, show'- rlig th arrangement of the slots or ports there- Figure 14 ia a. sideelevational view of an internal combustion engine, shown diagrammatically, and illustrating the application thereto o! one of the rotary compressors. blowers, or super--V f chargers embodying the invention.

is located within the housing and is journaled at one end in bearings 20 and at its opposite end 'in bearings 2|'. The end of the shaft I9 shown, .at the left of Figure 1 carries a gear 22 which is keyed to the shaft. This gear isfin mesh with an internally toothed Ygear v23 mounted upon a shaft 24 journaled in bearings 25 provided in the hubportion 26 of the housing end. The use of the internally toothed driving gear 23 is im- VAportant since by using such a driving gear, which follows the pitch of the internal or driven gear 22, which latter is always in mesh with the driving gear 23, the cylinder-and rotor can be turned through 180 degrees to permit the rotor to be driven in the opposite direction. The shaft 24 extends through a closure plate 21 and an oil seal or packing 21a which is carried by the plate. The plate is secured to the hub 26 by means of bolts 28'. The shaft 24 is drivingly connected with a drive shaft 30 from a power-plant, such as a two-cycle or four-cycle `internal combustion engine shown diagrammatically at 3l, by means of a coupling 29.

The driven shaft I9, it is trically mounted in hangers* located within the housing and carries a rotor 33. This rotor is provided with a plurality of radially extending pockets or slots 34 each of which is provided with a lining formed from some suitable wself-lubricatfree edge 36a. Theopposite end edges of the y blade 38 are notched out at 31 toreceive and support substantially cylindrical members or pins 33 which are secured to the blade by rivets or the like 39. Each of these members 38 carries a rockable block or contact member 40 provided with a socket or recess which has a relatively snug fitr with the member 38 yetwhich has suillclent freedom of movement to allow it to be oscillated or rocked relative to the member 38. The part 40 is preferably formed from material similar to the lining material35 such, for example, as sintered brass or bronze. .Y

It will be understood that as the rotor 33 revolves and as the successive vanes 33 are moved into their respective sockets or pockets 34, in

which position they are shown at the bottom of Fig. 2 and at the top of Fig. 3, the contact blocks 40 carried at the ends of the vanes move into their respective recesses 40a.,see particularly Figs. 8 and 1l.

Mounted concentrically within the housing or casing I5, is a cylinder or cylindrical member 42 provided with a plurality of longitudinally and circumferentially spaced slots or ports to be described hereinafter. This cylinder is, as shown,

to be noted, is eccenf provided at opposite ends with flanges `which engage and aresupported by so-called cylinder carriers or members 43 to which the cylinder is secured by means of bolts 44. The hangers \43 are supported by the outer housing in bearings i541 and Ila, respectively. Annular internal flanges on the hanger members 43 support, at the right-hand end of Figure 1, a bearing 4assembly 45 and at the left end, `a bearing assembly 45a. These bearing assemblies 45 and 45asupport a pair of similar guide rings 46 having inwardly directed annular ilanges with which the outer surfaces of the bearing Vblocks 40 are in contact.

It is to be noted, see particularly Figure 8 of the drawings, thatthe outer or free edges 362i of the vanes are located in proximity tothe inner surface or wall of the cylinder 42 but are maintained out of contact therewith by virtue of I the provision of the rings 46 and the contact blocks 4ll. Rings 46 are free to rotate on bearmental-like projection 55a.- The opposite end edges 55h of the projectionare adapted to engage the adjacent end edge-.of the block 53 as the cylinder 42 rotates a half revolution crapproximately 180 degrees` The ring 55 at the right end of Figures `1 or 4- is held in fixed position against the end of the housing by a cover plate 56 and bolts 56. The ring 55 at the left end of the cylinder 42 in Figures l and 4 is preferably fastened to the webor partition wall lla of the housing by bolts or cap screws 60. Atthis left end there is not provided a. cover plate such as plate 58 described above, because of the presence of the shaft end i9 and the gearing 22, 23 at this end of the housing. I

The exhaust side or section i1 of the housing ls'provided with a plurality of longitudinally spaced transversely extending ribs 54. These ribs may be of any desired shape in cross section so ings and 45a. Rings 46 are driven by friction y from contact blocks. The contact blocks, therefore, do not travel the whole circumference of the rings 46 but onlythe difference of the length of the arc at the outer and inner position of the contact blocks. Since the contactv blocks are I mounted for rocking movement relative' to'their supporting vanes, these blocks will conform to the contour of the inner surface of therings 46 during rotation of the rotor and vanes. By mainlong as their inner faces are ilat or straight across and the general over-all shape of the rib conforms to the contour `of the cylinder 42 with which they are in engagement, see especially Figures 2, 3 and ll. In cases where it is not desirable to compress the fluid before discharge, the ribs can be eliminated. Y

Referring particularly to Figures 11 and 13, the

y cylinder 42 is provided with two series of slots taining the outer edges 36a of the varies out of actual contact with the cylinder, friction and l wear are reduced to a minimum.

Referring particularly to Figure 10 of the drawings, I have shown a somewhat modied form of rotor vane or blade 41. As in the previous form, this vane is provided with notches at its opposite end edges to receive and support a substantially cylindrical member or pin 48 which is adapted toreceive and support a contact bloclrA or member 46. As in the previous form of invention, the member 46 Vmay be formed from some suitable self-lubricating material such, for example, as sintered brass or bronze. form of blade structure shown in Figure 10 comprises a blade whose outer or freeedge between the notched ends thereof is provided with a lon`- gitudinal slot or kerf to receive and support a 'Ilie particular strip or piece of-preferably non-metallic ma.-

terial such, for example, as hard rubber, fiber, Bakelite or othersuitable material. 4The strip, as shown, is secured in place by rivets 5I. The

purpose of yproviding the strip 56 is to ffill'the space between the outer edge of the blade ,or vane 41 and the adjacent wall of the cylinder `42 to thus prevent leakage of theair or'other fluid in the compressor. When the lparts are assembled the strips 56 have a relatively snug bearing flt with the wall of the cylinder 42 but as the rotor is driven, the strip will wear itself in and thus run free in the cylinder.v By virtue of the provision of such a strip it is not necessary to machine the cylinder to a close diametertolerance, but a close t will be maintained at all times. Moreover, by employing said strip is not necessary to provide an accurately machined cylinder wall; nor is it necessary that the outer edge of the vane 42 be accurately machined and smooth.

The outer face of each of the cylinder hangers 43 is provided with a segmental stop block 53 which, as shown, is bolted at 53a to the hanger although, if desired, these stop blocks may be formed integral with the hangers'.` Each of the opposite ends of the housing I5 supports a ring 55 provided with an inwardly extending segor ports 56, vv56 in` onehalf thereof and with two series of somewhat longer slots or ports,` 51, 51 in its other half. Ity will be seen that the series 56, 56 are staggered with relation to the series 51, v,51, i. e.the slots 56 are located at points in the cylindrical member which are between the slots 51. Thus, when the cylinder 42 is in its "position of Figures l1 and 13, the series of smaller slots or ports 56 will be behind and thus covered and sealed by the ribs 54, whereas the larger or longer slots or ports 51 will be located between the ribs 46 and thus open or exposed."

In, accordance with my invention, the working parts of the compressor which are normally subjected to frictibn and consequent wear are protected by the application thereto of lubricant in just sufllcient quantity to eliminate friction and prevent wear. f

"The varies 36 slide in the self-lubricating pocket lining metal 35 and, the contact members or blocks 40, also being formed from self-lubricating metal cause only slight wear`on the floating rings 46 on which they travel when the cornpressor is in operation.

The shaft i6 extends throughout the length of the rotor 33 and has adJacentits opposite ends annular recesses or grooves 6I which receive and support annular bands orstrips 62 of some suitable packing material, suchl as felt, which engage 'the surfaceof the shaft I9. Shaft I6 is drilled to provide an axial bore or passage 63 through which lubricant may flow and into transversely extending bores or passages 64` and 65 also formed`v` therein. One such passage or bore 64 communicates with a longitudinal pocket or recess 66 formed at the base of each of the pockets 34 formed in the rotor body 33, see particularly Figure 8. The transverse passages 65 feed lubricant to the packing rings 62 which become saturated so that some small quantity of the lubricant is supplied by centrifugal force through passages 61 to the contact blocks 40 to properly lubricate these blocks which are formed from a ysuitable* self-lubricating metal, as previously described. The ball or roller bearing assemblies of the compressor are properly lubricated in more or less conventional manner and thus all working parts angie? When power is applied to the driven shaft I3 oi' the compressor C fro'm the drive shaft 30 of ly well adapted for use as a supercharger for twol cycle or four-cycle engines. or, with the proper the power plant or engine E (Figure 14) through the coupling 29, shaft 24 and gearing 23, 22, the

` rotor 33 will be driven in a clockwise direction as indicated by the arrows in Figure 2. With the cylinder I2 in the position of Figures 2, 11 and 13, air or other fluid is drawn or sucked in through ports or slots 56 and 51 at the left of Figure 2, compressed by the vanes 36, and discharged through the -port or slot 51 at the right of Figure 2 tothe internal combustion engine or other power plant E to which it is attached. During this operation, the ports or slots 56 at the right side of cylinder 42 are covered and thus sealed by the ribs 54 and thus permits the air to be compressed until vane 36 reaches the opening 51.

If the engine E should be stopped and then run in the reverse direction, the rotor 33 is caused *to rotate in a counterclockwise direction as shown by the arrow in Figure 3. 'Such reversev rotation of the engine and rotor causes the cylinder 42 with the cylinder carriers 43 which have bearings 20 and 2| eccentrically mounted, to rotate 180 degrees on the bearings |641A and I1a to the position shown in Figure 3 and thus change or reverse the position of the rotor 33, drive shaft I9 and gear 22. The gear 22 at all times engages the internally toothed driving gear`23 and the unit turns until the stop block or segment 53 (see Figure 7) engages the stop or shoulder 55h at the bottom of Figure 7 in which position it remains. As the rotor 33 revolves i n a counterclockwise direction air or other fluid is sucked or drawn in through ports or slots 51 and 56 at the l left of Figure 3, is compressed by the vanes 36 and discharged through portsor slots. 51 at the right of Figure 3. The ports or slots 56 at the right side of the cylinder 42 are closed or sealed by the ribs 54. If now the engine E is again stopped and then run in the opposite direction, the cylinder 42 and rotor 33 will again shift through approximately 180 degrees until the opposite end of the stop block 53 contacts the stop portion or shoulder 55b of the ring 55 at the right.

arrangement of the slots I6 and 51, as a rotary pump for liquids. such as oil. many useful and utilitarian purposes which are not mentioned in the foregoing descriptive matter. Moreover. the novel features of my present invention, such as the lubricating features, the use of self-lubricating metal, etc., are equally well adapted for use in connection with a compressor` of the vane type which operates in one direction t* only.

Having thus described my invention, what I claim is:

1. A rotary compressor comprising a housing having intake and vexhaust openings formed therein, a drive shaft eccentrically mounted in said housing, a rotor provided with slidable radial vanes keyed to said shaft, a cylindrical member having a plurality of ports formed therein intert posed between the housing and rotor and'capable of oscillating movement within a limited range,

bearings in said housing for supporting the drive shaft, guide rings free to rotate within and located at opposite ends of said sleeve for maintaining the edges'of the vanes out of contact with the sleeve, anda plurality of longitudinally spaced transverse ribs located Within the housing at one side of said rotor, said ribsproviding means for covering certain f said ports when the cylindrical member is in one position relative to the intake and exhaust openings and others of said ports when said member is in another position.

2. In a rotary compressor of the sliding vane type for connection to a source of motive power,

the combination of a stationary housing having bearings adjacent the opposite ends thereof and having inlet and outlet openings, a cylindrical sleeve member located within the housing and` of slidable vanes, said rotor and shaft being ec-l centrically mounted with relation to said cylindrical sleeve, spaced stops located at opposite ends of said housing, a pinion carried by the extended portion of said rotor shaft, and an internally toothed gear rotatably mounted in anend wall of the housing constantly in mesh with said pinion and operatively connected with the power source whereby to revolve the rotor and vanes in either direction and at predetermined times to shift said cylindrical sleeve member and' end plates in opposite directions through approximately degrees between said spaced stops upon the reversal of rotation of said internally toothed gear.

ERLING BORSTING.

In fact, it has 

